A system for separating and recovering pharmaceutical production waste liquid

Abstract

The application discloses a medicine production waste liquid separation and recovery system, and belongs to the technical field of medicine production waste liquid separation and recovery.The separation and recovery system comprises a conical sedimentation chamber, a pulse backflush membrane assembly, a modular membrane package, a mixing tank and a micro vacuum pump.The mixing tank is used for containing medicine waste liquid or enrichment liquid.The slurry in the mixing tank is discharged into the conical sedimentation chamber.The conical sedimentation chamber is used for separating the slurry into large-particle impurities and suspension.The suspension comprises medium-particle and small-particle.The pulse backflush membrane assembly is used for separating the suspension into enrichment liquid and solvent permeate.The modular membrane package is used for separating the solvent permeate into enrichment liquid and high-concentration solvent.The application reduces the membrane pollution rate of the pulse backflush membrane assembly, realizes liquid level stability and concentration dynamic balance, improves the solid content control precision of the enrichment liquid, improves the recovery purity of the medicine production waste liquid and reduces the system operation energy consumption.

Description

Technical Field

[0001] This invention relates to the field of chemical pharmaceutical separation technology, and in particular to a drug production waste liquid separation and recovery system. Background Technology

[0002] In pharmaceutical manufacturing, wastewater recovery is a crucial step in ensuring environmental compliance and resource recycling. Early drug production relied on pressurized discharge, but air mixed into the liquid easily creates bubbles, affecting product quality. Furthermore, the recovery of highly toxic solvents in chemical and pharmaceutical processes, if conducted in an open environment, can easily lead to volatilization and leakage, endangering the environment and personnel safety. Miniature negative pressure separation systems, with their advantages of a closed, low-pressure environment, compact size, and low energy consumption, have become indispensable core equipment in this process, playing a significant role in improving the precision of wastewater treatment and reducing resource waste. However, existing miniature negative pressure separation systems still face several technical bottlenecks in practical applications: the complex composition and large viscosity fluctuations of pharmaceutical wastewater lead to unstable system processing efficiency and insufficient long-term operational reliability; limited by structural design and separation mechanisms, the number of separation stages is difficult to reach three or more, hindering the precise fractional recovery of multiple components in the wastewater; simultaneously, the lack of flexible and effective means to adjust the discharge concentration makes it difficult to adapt to the differentiated requirements of different drug manufacturing processes for wastewater treatment, severely restricting their widespread application and effectiveness in the field of pharmaceutical wastewater recovery. Summary of the Invention

[0003] To address the shortcomings of existing technologies, this application provides a pharmaceutical production waste liquid separation and recovery system to solve the technical problems existing in pharmaceutical production waste liquid separation and recovery systems, such as the inability to achieve accurate graded recovery of multiple components in the waste liquid and the difficulty in adjusting the discharge concentration.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] A pharmaceutical production waste liquid separation and recovery system includes a conical settling chamber, a pulse backflush membrane assembly, a modular membrane pack, a mixing tank, and a micro vacuum pump. The mixing tank is used to contain pharmaceutical waste liquid or enrichment liquid. The slurry in the mixing tank is discharged into the conical settling chamber, which is used to separate the slurry into large particulate impurities and a suspension. The suspension contains medium and small particles. The pulse backflush membrane assembly is used to separate the suspension into an enrichment liquid and a solvent permeate. The modular membrane pack is used to separate the solvent permeate into an enrichment liquid and a high-concentration solvent. Large particulate impurities refer to substances with a diameter >50μm, medium particles are substances with a diameter of 5-50μm, and small particles are substances with a diameter <50μm.

[0006] The mixing tank is equipped with a waste liquid inlet, an enrichment liquid inlet, and a slurry outlet. The pharmaceutical production waste liquid enters the mixing tank through the waste liquid inlet. The slurry outlet is connected to the feed inlet of the conical settling chamber. The slurry outlet is also connected to the inlet of the finished product tank. The finished product tank is used to contain the enrichment liquid with the required concentration. A valve is installed at the inlet of the finished product tank.

[0007] The conical settling chamber is formed by two cones, an upper cone and an lower cone. The pointed end of the lower cone faces downwards, and the pointed end of the upper cone faces upwards. The bottom surfaces of the two cones are circumferentially connected, and their central axes coincide. The inlet of the conical settling chamber is located on the surface of the upper cone. A valve is installed at the inlet, which is tangential, allowing the slurry to be sprayed into the conical settling chamber tangentially to the side wall of the upper cone. The slurry forms a stable downward spiral vortex within the chamber. The bottom of the conical settling chamber is uniformly provided with multiple compressed air nozzles. The air jets from the multiple compressed air nozzles rotate and rise, forming a collision angle of 50°-55° with the liquid vortex. The bottom of the conical settling chamber is provided with a large particle collection port for collecting large particulate impurities in the liquid. The upper cone is provided with a transition port, which is connected to the suspension inlet of the pulse backflush membrane module. The transition port is above the compressed air nozzles. The suspension containing medium and small particles flows to the pulse backflush membrane module through the transition port.

[0008] The pulse backflush membrane assembly is provided with a suspension inlet, a first enriched liquid outlet, and a solution permeate outlet. The modular membrane package is provided with a solution inlet, a second enriched liquid outlet, and a high-concentration solvent outlet. The suspension inlet is connected to the transition port, the first enriched liquid outlet is connected to the enriched liquid inlet of the mixing tank, the solution permeate outlet of the pulse backflush membrane assembly is connected to the solution inlet of the modular membrane package, the second enriched liquid outlet is connected to the enriched liquid inlet of the mixing tank, and the high-concentration solvent outlet is connected to the inlet of the solvent recovery tank. The outlet of the micro vacuum pump is connected to the mixing tank and the pulse backflush membrane assembly.

[0009] In one embodiment, the outlet of the micro vacuum pump is connected to the inlet of the vacuum buffer tank, and the outlet of the vacuum buffer tank is connected to the mixing tank and the pulse backflush membrane assembly.

[0010] In one embodiment, the slurry outlet of the mixing tank is connected to the inlet of the finished product tank and the feed inlet of the conical settling chamber via a drain pipe. A concentration detector is installed on the drain pipe to detect the concentration of small and medium-sized particles in the slurry. The control unit controls the opening of the valve at the inlet of the finished product tank, the opening of the valve at the feed inlet of the conical settling chamber, and the negative pressure of the pulse backflushing membrane assembly based on the detection results of the concentration detector. The control unit has a concentration threshold set. The control unit compares the detection results of the concentration detector with the set concentration threshold. If the slurry concentration is within the concentration threshold range, the valve at the inlet of the finished product tank is opened and the valve at the feed inlet of the conical settling chamber is closed, and the slurry that meets the requirements is discharged into the finished product tank. If the slurry concentration is higher than the concentration threshold, the valve at the inlet of the finished product tank is closed, the valve at the feed inlet of the conical settling chamber is opened, and the negative pressure of the pulse backflushing membrane assembly is reduced. If the slurry concentration is lower than the concentration threshold, the valve at the inlet of the finished product tank is closed, the valve at the feed inlet of the conical settling chamber is opened, and the negative pressure of the pulse backflushing membrane assembly is increased.

[0011] In one embodiment, the diameter of the feed inlet of the conical settling chamber is 15-25 mm, the velocity of the slurry entering the conical settling chamber is 10-12 m / s, a filter screen is installed at the feed inlet of the conical settling chamber, and a booster pump is installed at the slurry outlet of the mixing tank; the number of compressed air nozzles is [number missing], the diameter of the compressed air nozzles is 1.5-2.5 mm, the compressed air nozzles are connected to a micro air compressor, and the output pressure of the micro air compressor is 0.4-0.6 MPa; the diameter of the large particle collection port is 20-30 mm, a periodically operating micro start valve is installed at the large particle collection port, the periodic operation time of the micro start valve is less than 0.5 s, the distance between the transition port and the bottom of the conical settling chamber is 150-200 mm, and the diameter of the transition port is 20-30 mm.

[0012] In one embodiment, the cone angle of the lower cone in the conical settling chamber is 65°-75°, the height of the conical settling chamber is 300-500mm, the maximum diameter of the conical settling chamber is 180-250mm, the material of the conical settling chamber is 316L stainless steel or polytetrafluoroethylene, and a square cavity is provided at the apex of the upper cone in the conical settling chamber.

[0013] In one embodiment, the pulse backflush membrane assembly includes a cylindrical shell, inside which 100-200 silanized modified polyamide hollow fiber membrane filaments are vertically packed. The separation layer of the hollow fiber membrane filaments is grafted with C10-C12 alkyl chains. The water contact angle is 115°-125°, and the swelling rate is <2% for commonly used solvents in drug production, including ethanol and dichloromethane. The cylindrical shell is connected to a micro-vacuum pump. An annular micro-gas chamber is located at the top of the cylindrical shell. Multiple downward-opening pores are evenly distributed circumferentially within the annular micro-gas chamber. The annular micro-gas chamber is connected to a high-pressure micro-gas pump. A timed solenoid valve is installed between the annular micro-gas chamber and the high-pressure micro-gas pump. The suspension inlet is located at the bottom of the pulse backflush membrane assembly, and the first enriched liquid outlet and the solution permeate outlet are both located at the top of the pulse backflush membrane assembly.

[0014] In one embodiment, the cylindrical shell has a diameter of 80-120 mm and a height of 200-300 mm; the silanized modified polyamide hollow fiber membrane filaments have a diameter of 0.6-0.8 mm and a hollow pore size of 2-4 nm, with an effective filtration area of ​​0.8-1.5 m²; the micro vacuum pump provides a negative pressure range of -0.03 to 0.06 MPa to the pulse backflush membrane module; the high-pressure micro air pump outputs a pressure of 0.8-1.0 MPa; the pulse frequency of the timer solenoid valve is 2-3 Hz; and the duration of a single backflush is 80-120 ms; a booster pump is provided between the solution permeate outlet of the pulse backflush membrane module and the solution inlet of the modular membrane package.

[0015] In one embodiment, the modular membrane package includes a rectangular shell, within which a support layer, a transition layer, and a separation layer are sequentially disposed from top to bottom. The support layer is made of polyester nonwoven fabric with a diameter of 100-150 μm, a thickness of 0.2-0.3 mm, and a tensile strength > 150 N / cm. The transition layer is made of a polyimide nanofiber membrane with a thickness of 50-80 μm, an average pore size of 30-40 nm, and is prepared by electrospinning. The surface charge density of the polyimide nanofiber membrane is -0.8 to -1.0 mC / m². The separation layer is a silanized polyamide layer with a thickness of 10-15 μm, a pore size of 2-4 nm, and is grafted with C10. Alkyl chains form a molecular-level hydrophobic barrier; the solution inlet is located at the upper part of the rectangular shell, the high-concentration solvent outlet is located at the bottom of the rectangular shell, and the second enrichment liquid outlet is located between the transition layer and the separation layer.

[0016] In one embodiment, a drain tank is installed between the modular membrane pack and the solvent recovery tank. The inlet of the drain tank is connected to the high-concentration solvent outlet of the modular membrane pack, and the outlet of the drain tank is connected to the inlet of the solvent recovery tank. A capacitive low-level gauge is installed on the lower side of the drain tank, and an ultrasonic high-level gauge is installed on the upper side of the drain tank. The distance between the capacitive low-level gauge and the lower end of the drain tank is 30-50 mm, used for contact detection of the thickness of the residual liquid layer at the bottom of the drain tank, thereby controlling the residual amount in the drain tank. The distance between the ultrasonic high-level gauge and the upper end of the drain tank is 50-80 mm, used for non-contact monitoring of the liquid level peak, avoiding direct contact with the drug waste liquid and causing contamination. A large water pump and a small water pump are connected in parallel between the outlet of the drain tank and the inlet of the solvent recovery tank. The flow rate of the large water pump is greater than that of the small water pump. The inlets of both the large and small water pumps are connected to the outlet of the drain tank, and the outlets of both the large and small water pumps are connected to the inlet of the solvent recovery tank. The system is configured with high-level, transitional, and low-level liquid level thresholds from top to bottom. When the liquid level in the drain tank is between the high-level and transitional thresholds, an ultrasonic high-level gauge is triggered. When the liquid level in the drain tank is below the low-level threshold, a capacitive low-level gauge is triggered. If the ultrasonic high-level gauge is continuously triggered and the capacitive low-level gauge is not triggered, the drain tank is determined to be truly full, and a large water pump is activated to quickly drain the liquid from the drain tank to prevent overflow. When the liquid level in the drain tank is below the transition level but above the low level threshold, neither the ultrasonic high-level gauge nor the capacitive low-level gauge is triggered. The large water pump stops working, and the small water pump starts working to slowly drain the liquid from the drain tank. When the liquid level in the drain tank is at the low level threshold, the ultrasonic high-level gauge is not triggered, but the capacitive low-level gauge is triggered. Then both the large and small water pumps stop working, and the drain tank is shut off. One-way check valves are installed at the outlets of both the large and small water pumps.

[0017] In one embodiment, a U-shaped siphon is provided between the first enrichment outlet of the pulse backflushing membrane assembly and the enrichment inlet of the mixing tank. The U-shaped siphon has a high-level port and a low-level port, with the high-level port being higher than the low-level port. The first enrichment outlet is connected to the high-level port of the U-shaped siphon, and the second enrichment outlet of the modular membrane package is also connected to the high-level port of the U-shaped siphon. The low-level port is connected to the enrichment inlet of the mixing tank.

[0018] Compared with the prior art, this application has at least the following beneficial effects:

[0019] This invention utilizes the conical structure and aerodynamic vortex enhancement design of the circulating settling chamber to create a stable spiral vortex at a tangential feed velocity of 10-12 m / s. This achieves efficient three-stage separation of particles >50 μm, 5-50 μm, and <5 μm in pharmaceutical production wastewater. Combined with a pulse backflush membrane module and a U-shaped siphon self-return channel, precise retention and shear-free recirculation of small particles are achieved under a negative pressure of -0.03 to -0.06 MPa, reducing the membrane fouling rate of the pulse backflush membrane module by 80%. The unit unit, through capacitive-ultrasonic dual-level sensing interlock and linkage with large and small pumps, combined with a concentration detector, achieves stable liquid level and dynamic concentration balance in the drain tank during the drainage process, enabling the solid content control accuracy of the enriched solution to reach ±1%. The modular membrane package, relying on a polyester-polyimide-silanized polyamide three-layer composite structure, maintains a swelling rate of <2% in strong solvent environments, ultimately achieving a comprehensive technical effect of drug waste liquid recovery purity >99.5%, energy consumption reduction of 40%, and compatibility with various drug solvent systems. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure of the drug production waste liquid separation and recovery system in an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the conical settling chamber in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the structure of the pulse backflush membrane assembly in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the modular membrane package structure in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the U-shaped siphon tube in an embodiment of the present invention.

[0025] Reference numerals: 1. Conical settling chamber; 2. Pulse backflush membrane assembly; 201. Cylindrical shell; 202. Hollow fiber membrane filament; 203. Annular micro gas chamber; 3. Modular membrane package; 301. Rectangular shell; 302. Support layer; 303. Transition layer; 304. Separation layer; 4. Mixing tank; 5. U-shaped siphon tube; 6. Concentration detector; 7. Control unit; 8. Finished product tank; 9. Solvent recovery tank; 10. Drainage tank; 1001. Large water pump; 1002. Small water pump; 1003. Ultrasonic high level gauge; 1004. Capacitive low level gauge; 11. Miniature vacuum pump; 1101. Vacuum buffer tank; 12. Booster pump. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of this invention clearer, the invention is described below with reference to specific embodiments shown in the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and technologies are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0027] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. The singular forms “a,” “the,” and “the” as used in this disclosure and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0028] It should be understood that although the terms first, second, third, etc., may be used in this disclosure to describe various information, such information should not be limited to these terms and should not be construed as indicating or implying relative importance. These terms are used only to distinguish information of the same type from one another. For example, without departing from the scope of this disclosure, first information may also be referred to as second information, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to determination."

[0029] In the description of this invention, unless otherwise specified and limited, it should be noted that the terms "installation", "connection" and "linking" should be interpreted broadly. For example, they can refer to mechanical connection or internal connection between two components. They can be direct connection or indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0030] To better understand the technical solution of the present invention, the present invention will be described in detail below with reference to the embodiments and accompanying drawings.

[0031] This embodiment provides a pharmaceutical production waste liquid separation and recovery system, as shown in the attached figure, including a conical settling chamber 1, a pulse backflush membrane assembly 2, a modular membrane pack 3, a mixing tank 4, a micro vacuum pump 11, and a control unit 7. The mixing tank 4 is used to contain pharmaceutical waste liquid or enrichment liquid. The slurry in the mixing tank 4 is discharged to the conical settling chamber 1. The conical settling chamber 1 is used to separate the slurry into large particulate impurities and suspension. The suspension contains medium and small particles. The pulse backflush membrane assembly 2 is used to separate the suspension into enrichment liquid and solvent permeate. The modular membrane pack 3 is used to separate the solvent permeate into enrichment liquid and high-concentration solvent. Large particulate impurities refer to substances with a diameter >50μm, medium particles are substances with a diameter of 5-50μm, and small particles are substances with a diameter <50μm.

[0032] The mixing tank 4 is equipped with a waste liquid inlet, an enrichment liquid inlet, and a slurry outlet. The pharmaceutical production waste liquid enters the mixing tank 4 through the waste liquid inlet. The slurry outlet is connected to the feed inlet of the conical settling chamber 1. The slurry outlet is also connected to the inlet of the finished product tank 8. The finished product tank 8 is used to contain the enrichment liquid with the required concentration. A valve is installed at the inlet of the finished product tank 8.

[0033] As attached Figure 2 As shown, the conical settling chamber 1 is formed by two cones, an upper cone and an lower cone. The pointed end of the lower cone faces downwards, and the pointed end of the upper cone faces upwards. The bottom surfaces of the two cones are circumferentially connected, and their central axes coincide. The feed inlet of the conical settling chamber 1 is located on the surface of the upper cone. A valve is installed at the feed inlet of the conical settling chamber 1. The feed inlet is tangential, allowing the slurry to be sprayed into the conical settling chamber 1 in a direction tangential to the side wall of the upper cone. The slurry forms a stable spiral downward vortex within the chamber. Multiple pressure points are evenly arranged circumferentially at the bottom of the conical settling chamber 1. The compressed air nozzles spray air in a rotating, rising airflow that forms a 50°-55° collision angle with the liquid vortex. This enhances the collision and aggregation of particles (such as drug microcrystals and excipient particles) in the drug waste liquid, accelerating the settling of large particles. The bottom of the conical settling chamber 1 is equipped with a large particle collection port for collecting large particulate impurities in the liquid. A transition port is provided on the upper cone, which is connected to the suspension inlet of the pulse backflush membrane assembly 2. The transition port is located above the compressed air nozzles, and the suspension containing medium and small particles flows to the pulse backflush membrane assembly 2 through the transition port.

[0034] The pulse backflush membrane module 2 is provided with a suspension inlet, a first enriched liquid outlet, and a solution permeate outlet. The modular membrane package 3 is provided with a solution inlet, a second enriched liquid outlet, and a high-concentration solvent outlet. The suspension inlet is connected to the transition port, the first enriched liquid outlet is connected to the enriched liquid inlet of the mixing tank 4, the solution permeate outlet of the pulse backflush membrane module 2 is connected to the solution inlet of the modular membrane package 3, the second enriched liquid outlet is connected to the enriched liquid inlet of the mixing tank 4, and the high-concentration solvent outlet is connected to the inlet of the solvent recovery tank 9.

[0035] The outlet of the miniature vacuum pump 11 is connected to the mixing tank 4 and the pulse backflush membrane assembly 2 to maintain the negative pressure working environment of the system. In order to stabilize the system operating pressure and protect the miniature vacuum pump 11, in this embodiment, the outlet of the miniature vacuum pump 11 is connected to the inlet of the vacuum buffer tank 1101, and the outlet of the vacuum buffer tank 1101 is connected to the mixing tank 4 and the pulse backflush membrane assembly 2.

[0036] The slurry outlet of mixing tank 4 is connected to the inlet of finished product tank 8 and the feed inlet of conical settling chamber 1 via a drain pipe. A concentration detector 6 is installed on the drain pipe to detect the concentration of small and medium-sized particles in the slurry. Control unit 7 controls the valve opening at the inlet of finished product tank 8, the valve opening at the feed inlet of conical settling chamber 1, and the negative pressure of pulse backflushing membrane assembly 2 based on the results detected by concentration detector 6. Control unit 7 has a set concentration threshold, which is specified according to drug recovery requirements. In this embodiment, the concentration threshold for small and medium-sized particles in the slurry is a solid content of 5%-15%. Control unit 7 compares the detection results of concentration detector 6 with the set concentration threshold. If the slurry concentration is within the concentration threshold range, the valve at the inlet of finished product tank 8 is opened, and the valve at the feed inlet of conical settling chamber 1 is closed, discharging the compliant slurry into finished product tank 8. If the slurry concentration is higher than the concentration threshold, the valve at the inlet of finished product tank 8 is closed, the valve at the feed inlet of conical settling chamber 1 is opened, and the negative pressure of pulse backflushing membrane assembly 2 is reduced to - 0.03-0.04MPa, slow down the filtration speed and dilute the slurry. If the slurry concentration is lower than the concentration threshold, close the valve at the inlet of the finished product tank 8, open the valve at the feed inlet of the conical settling chamber 1, and increase the negative pressure of the pulse backflushing membrane assembly 2 to -0.05-0.06MPa to accelerate liquid penetration through the membrane and concentrate the slurry. The control unit 7 has a control time of less than 5 seconds.

[0037] In this embodiment, the concentration detector 6 is a miniature online refractometer. The miniature online refractometer detects the refractive index of the waste drug solution in real time and calculates the concentration using a preset calibration curve (derived from an experiment correlating the target solute concentration and refractive index in the slurry). The miniature online refractometer has a measurement range of 0-30% Brix, an accuracy of ±0.05% Brix, and is made of 316L stainless steel.

[0038] The diameter of the feed inlet of the conical settling chamber 1 is 15-25 mm, and the velocity of the slurry entering the conical settling chamber 1 is 10-12 m / s. A 100-mesh filter screen is installed at the feed inlet of the conical settling chamber 1 to initially intercept large impurities (such as clumps of drug residue) that may be present in the drug waste liquid. To ensure the velocity of the slurry entering the conical settling chamber 1, a booster pump 12 is installed at the slurry outlet of the mixing tank 4.

[0039] The number of compressed air nozzles is 6-8, the diameter of the compressed air nozzles is 1.5-2.5mm, the compressed air nozzles are connected to the micro air compressor, and the output pressure of the micro air compressor is 0.4-0.6Mpa.

[0040] The diameter of the large particle collection port is 20-30mm. A periodically operating miniature start valve is installed at the large particle collection port to periodically discharge settled large particle impurities. The periodic operation time of the miniature start valve is less than 0.5 seconds. The distance between the transition port and the bottom of the conical settling chamber 1 is 150-200mm, and the diameter of the transition port is 20-30mm.

[0041] The cone angle of the lower cone in the conical settling chamber 1 is 65°-75°, the height of the conical settling chamber 1 is 300-500mm, and the maximum diameter of the conical settling chamber 1 is 180-250mm. The material of the conical settling chamber 1 is 316L stainless steel, which is resistant to corrosion by pharmaceutical waste liquid, or polytetrafluoroethylene, which is suitable for strong solvent pharmaceutical waste liquid. A square cavity is set at the apex of the upper cone in the conical settling chamber 1 to enhance the vortex collision within the conical settling chamber 1.

[0042] As attached Figure 3 As shown, the pulse backflush membrane assembly 2 includes a cylindrical shell 201, inside which 100-200 silanized modified polyamide hollow fiber membrane filaments 202 are vertically packed. The separation layer of the hollow fiber membrane filaments is grafted with C10-C12 alkyl chains. The water contact angle is 115°-125°, and the swelling rate is <2% for commonly used solvents in drug production, including ethanol and dichloromethane. The cylindrical shell is connected to a micro vacuum pump 11. An annular micro gas chamber 203 is located at the top of the cylindrical shell. The annular micro gas chamber 203 has multiple downward-opening pores evenly distributed circumferentially. The annular micro gas chamber 203 is connected to a high-pressure micro gas pump. A timed solenoid valve is installed between the annular micro gas chamber 203 and the high-pressure micro gas pump. The suspension inlet is located at the bottom of the pulse backflush membrane assembly 2, and the first enriched liquid outlet and the solution permeate outlet are both located at the top of the pulse backflush membrane assembly 2. When the pulse backflush membrane module 2 is working, the negative pressure drives the suspension through the membrane layer, and small particles (such as drug small molecule impurities and colloidal particles) are trapped on the membrane surface to form a filter cake layer to complete the forward filtration. The annular micro gas chamber 203 is periodically introduced with high-pressure gas to reverse the pressure difference, efficiently peel off the filter cake layer, avoid the decrease in drug retention efficiency caused by membrane pore blockage, and the peeled filter cake dissolves into the suspension.

[0043] The cylindrical shell 201 has a diameter of 80-120 mm and a height of 200-300 mm. The diameter of the silanized modified polyamide hollow fiber membrane filaments is 0.6-0.8 mm, the pore size is 2-4 nm, and the effective filtration area is 0.8-1.5 m². The micro vacuum pump 11 provides a negative pressure range of -0.03 to 0.06 MPa to the pulse backflush membrane module 2, the pressure output by the high-pressure micro air pump is 0.8-1.0 MPa, the pulse frequency of the timing solenoid valve is 2-3 Hz, and the duration of a single backflush is 80-120 ms. To increase the speed at which the solvent permeate enters the modular membrane package 3, a booster pump 12 is installed between the solution permeate outlet of the pulse backflush membrane module 2 and the solution inlet of the modular membrane package 3.

[0044] As attached Figure 4 As shown, the modular membrane package 3 includes a rectangular shell 301 with dimensions of 150×80×50mm. Inside the rectangular shell 301, from top to bottom, are a support layer 302, a transition layer 303, and a separation layer 304. The support layer 302 is made of polyester nonwoven fabric with a diameter of 100-150μm and a thickness of 0.2-0.3mm. The tensile strength of the support layer 302 is >150N / cm. The support layer 302 is used to intercept impurities >100μm (such as drug residue and large-particle excipients) in drug waste. The transition layer 303 is made of polyimide nanofiber membrane with a thickness of 50-80μm and an average pore size of 30-40nm. The polyimide nanofiber membrane is prepared by electrospinning, and its surface charge density is - The transition layer 303, with a concentration of 0.8–1.0 mC / m², is used to adsorb colloidal particles (such as proteins and polymer impurities) in the pharmaceutical waste liquid. The separation layer 304 is a silanized polyamide layer with a thickness of 10–15 μm and a pore size of 2–4 nm. The silanized polyamide layer is grafted with C10 alkyl chains to form a molecular-level hydrophobic barrier, which blocks the interaction between commonly used solvents in pharmaceutical production (such as methanol and ethyl acetate) and the membrane substrate, while retaining small molecule impurities (<5 μm) to ensure that the purity of the recovered solvent is > 99.5%. The solution inlet is located at the top of the rectangular shell 301, the high-concentration solvent outlet is located at the bottom of the rectangular shell 301, and the second enrichment liquid outlet is located between the transition layer 303 and the separation layer 304.

[0045] To temporarily store the obtained high-concentration solvent and balance the flow fluctuations of the high-concentration solvent, a drain tank 10 is installed between the modular membrane package 3 and the solvent recovery tank 9. The inlet of the drain tank 10 is connected to the high-concentration solvent outlet of the modular membrane package 3, and the outlet of the drain tank 10 is connected to the inlet of the solvent recovery tank 9. The volume of the drain tank 10 is 5-10L. A capacitive low-level gauge 1004 is installed on the lower side of the drain tank 10, and an ultrasonic high-level gauge 1003 is installed on the upper side of the drain tank 10. The distance between the capacitive low-level gauge 1004 and the lower end of the drain tank 10 is 30-50mm, which is used to detect the thickness of the residual liquid layer at the bottom of the drain tank 10 in a contact manner, thereby controlling the residual amount in the drain tank 10 to be not less than 50mL. The distance between the ultrasonic high-level gauge 1003 and the upper end of the drain tank 10 is 50-80mm. The ultrasonic high-level gauge 1003 is used to monitor the peak liquid level in a non-contact manner, avoiding direct contact with the drug waste liquid and causing pollution. A large water pump 1001 and a small water pump 1002 are connected in parallel between the outlet of the drain tank 10 and the inlet of the solvent recovery tank 9. The flow rate of the large water pump 1001 is greater than that of the small water pump 1002. The inlets of both the large water pump 1001 and the small water pump 1002 are connected to the outlet of the drain tank 10, and the outlets of both the large water pump 1001 and the small water pump 1002 are connected to the inlet of the solvent recovery tank 9. The drain tank 10 is equipped with a high liquid level threshold and a transition liquid level from top to bottom. In this embodiment, the volume below the high liquid level threshold accounts for 80% of the tank volume of the drain tank 10, the volume below the transition liquid level accounts for 30% of the tank volume of the drain tank 10, and the volume below the low liquid level threshold accounts for 20% of the tank volume of the drain tank 10. When the liquid level in the drain tank 10 is between the high liquid level threshold and the transition liquid level, the ultrasonic high level gauge 1003 is triggered; when the liquid level in the drain tank 10 is lower than the low liquid level threshold, the ultrasonic high level gauge 1003 is triggered. Capacitive low-level gauge 1004; when ultrasonic high-level gauge 1003 is continuously triggered and capacitive low-level gauge 1004 is not triggered, the drain tank 10 is determined to be in a true full state, and the large water pump 1001 is started to quickly drain the liquid from the drain tank 10 to prevent overflow; when the liquid level in the drain tank 10 is lower than the transition liquid level and higher than the low-level liquid level threshold, neither ultrasonic high-level gauge 1003 nor capacitive low-level gauge 1004 is triggered, and the large water pump 1001 is started to work to quickly drain the liquid from the drain tank 10 to prevent overflow; when the liquid level in the drain tank 10 is lower than the transition liquid level and higher than the low-level liquid level threshold, neither ultrasonic high-level gauge 1003 nor capacitive low-level gauge 1004 is triggered, the large water pump 1001 is started to work. When pump 1001 stops working, pump 1002 starts working to slowly discharge the liquid from drain tank 10. When the liquid level in drain tank 10 is at the low level threshold, the ultrasonic high level gauge 1003 is not triggered, but the capacitive low level gauge 1004 is triggered. Then, both pump 1001 and pump 1002 stop working, shutting off the discharge from drain tank 10 to maintain a negative pressure (-0.03 to 0.05 MPa) by preserving the bottom liquid seal. One-way check valves are installed at the outlets of both pump 1001 and pump 1002 to prevent backflow and cross-contamination when the negative pressure environment is disrupted.

[0046] In this embodiment, the capacitive low-level gauge has a measurement accuracy of ±0.5mm and is made of PTFE, while the ultrasonic high-level gauge has a measurement accuracy of ±1mm and a range of 0-500mm. The large water pump 1001 is a miniature pneumatic diaphragm pump with a flow rate of 50-100L / h and a head of 5-8m. The small water pump 1002 is a miniature gear pump with a flow rate of 10-20L / h and a head of 3-5m. Both the large water pump 1001 and the small water pump 1002 are made of 316L stainless steel to prevent corrosion from pharmaceutical waste liquid.

[0047] A U-shaped siphon 5 is installed between the first enrichment outlet of the pulse backflushing membrane module 2 and the enrichment inlet of the mixing tank 4. The U-shaped siphon 5 has a high-level port and a low-level port, with the high-level port being higher than the low-level port. The first enrichment outlet is connected to the high-level port of the U-shaped siphon 5, and the second enrichment outlet of the modular membrane package 3 is also connected to the high-level port of the U-shaped siphon. The low-level port is connected to the enrichment inlet of the mixing tank 4. By installing the U-shaped siphon, the enrichment automatically flows back to the mixing tank 4 under the action of system negative pressure (-0.02 to -0.04 MPa), and there is no mechanical impeller shearing conveying of the particle enrichment.

[0048] The top of the U-shaped siphon 5 is equipped with a vacuum breaker valve with an opening pressure of -0.01 MPa to prevent liquid backflow in case of abnormal negative pressure in the system. A one-way valve is installed at the lower port to prevent liquid from the mixing tank 4 from flowing back into the U-shaped siphon. The diameter of the U-shaped siphon is 10-15 mm, and the material is PTFE.

[0049] In this embodiment, the working principle of the drug production waste liquid separation and recovery system is as follows:

[0050] A portion of the pharmaceutical production wastewater enters the mixing tank 4 and then flows through the booster pump 12 into the conical settling chamber 1. In the settling chamber 1, the wastewater is separated into large particles and a suspension containing small to medium-sized particles. The suspension then enters the pulse backflush membrane module 2, where it is separated into a concentrated solution containing small to medium-sized particles and a solvent permeate. The solvent permeate enters the modular membrane pack 3, where it is separated into a concentrated solution and a high-concentration solvent (up to 99.5%). The high-concentration solvent flows through the discharge tank 10 into the solvent recovery tank 9, where it is used for solvent recovery. The concentrated solution separated by the pulse backflush membrane module 2 and the modular membrane pack 3 re-enter the mixing tank 4. A concentration detector measures the concentration of the concentrated solution discharged from the mixing tank 4. If the concentration meets the standard, it enters the finished product tank 8. The concentrated solution in the finished product tank 8 is used to recover antibiotics, etc. If the concentration does not meet the standard, it re-enters the conical settling chamber 1 for a new round of separation and filtration until the concentrated solution reaches the standard and enters the finished product tank 8. New pharmaceutical production wastewater then re-enters the mixing tank 4 for separation and recovery. The enriched solution in finished product tank 8 can be used to extract antibiotics, and the high-concentration solvent in solvent recovery tank 9 can be used to extract IPA (isopropanol).

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.

Claims

1. A pharmaceutical production waste liquid separation and recovery system, characterized in that, The system includes a conical settling chamber, a pulse backflush membrane assembly, a modular membrane pack, a mixing tank, and a micro vacuum pump. The mixing tank is used to contain drug waste liquid or enrichment liquid. The slurry in the mixing tank is discharged into the conical settling chamber, which is used to separate the slurry into large particulate impurities and a suspension. The suspension contains medium and small particles. The pulse backflush membrane assembly is used to separate the suspension into an enrichment liquid and a solvent permeate. The modular membrane pack is used to separate the solvent permeate into an enrichment liquid and a high-concentration solvent. Large particulate impurities refer to substances with a diameter >50μm, medium particles are substances with a diameter of 5-50μm, and small particles are substances with a diameter <5μm. The mixing tank is equipped with a waste liquid inlet, an enrichment liquid inlet, and a slurry outlet. The pharmaceutical production waste liquid enters the mixing tank through the waste liquid inlet. The slurry outlet is connected to the feed inlet of the conical settling chamber. The slurry outlet is also connected to the inlet of the finished product tank. The finished product tank is used to contain the enrichment liquid with the required concentration. A valve is installed at the inlet of the finished product tank. The conical settling chamber is formed by two cones, an upper cone and an lower cone. The pointed end of the lower cone faces downwards, and the pointed end of the upper cone faces upwards. The bottom surfaces of the two cones are circumferentially connected, and their central axes coincide. The inlet of the conical settling chamber is located on the surface of the upper cone. A valve is installed at the inlet, which is tangential, allowing the slurry to be sprayed into the conical settling chamber tangentially to the side wall of the upper cone. The slurry forms a stable downward spiral vortex within the chamber. The bottom of the conical settling chamber is uniformly provided with multiple compressed air nozzles. The air jets from the multiple compressed air nozzles rotate and rise, forming a collision angle of 50°-55° with the liquid vortex. The bottom of the conical settling chamber is provided with a large particle collection port for collecting large particulate impurities in the liquid. The upper cone is provided with a transition port, which is connected to the suspension inlet of the pulse backflush membrane module. The transition port is above the compressed air nozzles. The suspension containing medium and small particles flows to the pulse backflush membrane module through the transition port. The pulse backflush membrane assembly is provided with a suspension inlet, a first enriched liquid outlet, and a solution permeate outlet. The modular membrane package is provided with a solution inlet, a second enriched liquid outlet, and a high-concentration solvent outlet. The suspension inlet is connected to the transition port, the first enriched liquid outlet is connected to the enriched liquid inlet of the mixing tank, the solution permeate outlet of the pulse backflush membrane assembly is connected to the solution inlet of the modular membrane package, the second enriched liquid outlet is connected to the enriched liquid inlet of the mixing tank, and the high-concentration solvent outlet is connected to the inlet of the solvent recovery tank. The outlet of the micro vacuum pump is connected to the mixing tank and the pulse backflush membrane assembly. The outlet of the micro vacuum pump is connected to the inlet of the vacuum buffer tank, and the outlet of the vacuum buffer tank is connected to the mixing tank and the pulse backflush membrane assembly. It also includes a control unit. The slurry outlet of the mixing tank is connected to the inlet of the finished product tank and the feed inlet of the conical settling chamber through a drain pipe. A concentration detector is installed on the drain pipe to detect the concentration of small and medium-sized particles in the slurry. The control unit controls the valve opening at the inlet of the finished product tank, the valve opening at the feed inlet of the conical settling chamber, and the negative pressure of the pulse backflushing membrane assembly based on the detection results of the concentration detector. The control unit is set with a concentration threshold. The control unit compares the detection results of the concentration detector with the set concentration threshold. If the slurry concentration is within the concentration threshold range, the valve at the inlet of the finished product tank is opened and the valve at the feed inlet of the conical settling chamber is closed, and the slurry that meets the requirements is discharged into the finished product tank. If the slurry concentration is higher than the concentration threshold, the valve at the inlet of the finished product tank is closed and the valve at the feed inlet of the conical settling chamber is opened, and the negative pressure of the pulse backflushing membrane assembly is reduced. If the slurry concentration is lower than the concentration threshold, the valve at the inlet of the finished product tank is closed and the valve at the feed inlet of the conical settling chamber is opened, and the negative pressure of the pulse backflushing membrane assembly is increased. The diameter of the feed inlet of the conical settling chamber is 15-25mm, and the velocity of the slurry entering the conical settling chamber is 10-12m / s. A filter screen is installed at the feed inlet of the conical settling chamber, and a booster pump is installed at the slurry outlet of the mixing tank. The number of compressed air nozzles is [number missing], and the diameter of the compressed air nozzles is 1.5-2.5mm. The compressed air nozzles are connected to a micro air compressor, and the output pressure of the micro air compressor is 0.4-0.6Mpa. The diameter of the large particle collection port is 20-30mm, and a periodically operating micro start valve is installed at the large particle collection port. The periodic operation time of the micro start valve is less than 0.5S. The distance between the transition port and the bottom of the conical settling chamber is 150-200mm, and the diameter of the transition port is 20-30mm. The pulse backflush membrane assembly includes a cylindrical shell, inside which 100-200 silanized modified polyamide hollow fiber membrane filaments are vertically packed. The separation layer of the hollow fiber membrane filaments is grafted with C10-C12 alkyl chains. The water contact angle is 115°-125°, and the swelling rate of commonly used solvents in drug production is <2%. Commonly used solvents include ethanol and dichloromethane. The cylindrical shell is connected to a micro vacuum pump. An annular micro gas chamber is provided at the top of the cylindrical shell. The annular micro gas chamber has multiple downward-opening pores evenly arranged circumferentially. The annular micro gas chamber is connected to a high-pressure micro gas pump. A timed solenoid valve is provided between the annular micro gas chamber and the high-pressure micro gas pump. The suspension inlet is located at the bottom of the pulse backflush membrane assembly, and the first enriched liquid outlet and the solution permeate outlet are both located at the top of the pulse backflush membrane assembly. The modular membrane package includes a rectangular shell, within which a support layer, a transition layer, and a separation layer are sequentially arranged from top to bottom. The support layer is made of polyester nonwoven fabric with a diameter of 100-150 μm and a thickness of 0.2-0.3 mm, with a tensile strength > 150 N / cm. The transition layer is made of polyimide nanofiber membrane with a thickness of 50-80 μm and an average pore size of 30-40 nm. The polyimide nanofiber membrane is prepared by electrospinning and has a surface charge density of -0.8 to 1.0 mC / m². The separation layer is a silanized polyamide layer with a thickness of 10-15 μm and a pore size of 2-4 nm. The silanized polyamide layer is grafted with C10 alkyl chains to form a molecular-level hydrophobic barrier. The solution inlet is located at the top of the rectangular shell, the high-concentration solvent outlet is located at the bottom of the rectangular shell, and the second enrichment liquid outlet is located between the transition layer and the separation layer. A U-shaped siphon is provided between the first enrichment outlet of the pulse backflushing membrane assembly and the enrichment inlet of the mixing tank. The U-shaped siphon has a high-level port and a low-level port, with the high-level port being higher than the low-level port. The first enrichment outlet is connected to the high-level port of the U-shaped siphon, and the second enrichment outlet of the modular membrane package is also connected to the high-level port of the U-shaped siphon. The low-level port is connected to the enrichment inlet of the mixing tank.

2. The separation and recovery system according to claim 1, characterized in that, The cone angle of the lower cone in the conical settling chamber is 65°-75°, the height of the conical settling chamber is 300-500mm, the maximum diameter of the conical settling chamber is 180-250mm, the material of the conical settling chamber is 316L stainless steel or polytetrafluoroethylene, and a square cavity is provided at the apex of the upper cone in the conical settling chamber.

3. The separation and recovery system according to claim 1, characterized in that, The cylindrical shell has a diameter of 80-120mm and a height of 200-300mm. The silanized modified polyamide hollow fiber membrane filaments have a diameter of 0.6-0.8mm and a hollow pore size of 2-4nm, with an effective filtration area of ​​0.8-1.5m². The micro vacuum pump provides a negative pressure range of -0.03 to 0.06MPa to the pulse backflush membrane module, the high-pressure micro air pump outputs a pressure of 0.8-1.0MPa, the pulse frequency of the timer solenoid valve is 2-3Hz, and the duration of a single backflush is 80-120ms. A booster pump is installed between the solution permeate outlet of the pulse backflush membrane module and the solution inlet of the modular membrane package.

4. The separation and recovery system according to claim 1, characterized in that, A drain tank is installed between the modular membrane pack and the solvent recovery tank. The inlet of the drain tank is connected to the high-concentration solvent outlet of the modular membrane pack, and the outlet of the drain tank is connected to the inlet of the solvent recovery tank. A capacitive low-level gauge is installed on the lower side of the drain tank, and an ultrasonic high-level gauge is installed on the upper side. The distance between the capacitive low-level gauge and the lower end of the drain tank is 30-50mm, used for contact detection of the thickness of the residual liquid layer at the bottom of the drain tank, thereby controlling the residual amount in the drain tank. The distance between the ultrasonic high-level gauge and the upper end of the drain tank is 50-80mm, used for non-contact monitoring of the liquid level peak, avoiding direct contact with the drug waste liquid and causing contamination. A large water pump and a small water pump are connected in parallel between the outlet of the drain tank and the inlet of the solvent recovery tank. The flow rate of the large water pump is greater than that of the small water pump. The inlets of both the large and small water pumps are connected to the outlet of the drain tank, and the outlets of both the large and small water pumps are connected to the inlet of the solvent recovery tank. The drain tank is equipped with a top-to-bottom... The system is equipped with high-level, transitional, and low-level liquid thresholds. When the liquid level in the drain tank is between the high-level and transitional thresholds, an ultrasonic high-level gauge is triggered. When the liquid level in the drain tank is below the low-level threshold, a capacitive low-level gauge is triggered. When the ultrasonic high-level gauge is continuously triggered and the capacitive low-level gauge is not triggered, the drain tank is determined to be truly full, and the large water pump is activated to quickly drain the liquid from the drain tank to prevent overflow. When the liquid level in the drain tank is below the transitional level but above the low-level threshold, neither the ultrasonic high-level gauge nor the capacitive low-level gauge is triggered. The large water pump stops working, and the small water pump operates to slowly drain the liquid from the drain tank. When the liquid level in the drain tank is at the low-level threshold, the ultrasonic high-level gauge is not triggered, but the capacitive low-level gauge is triggered. Both the large and small water pumps stop working, and the drain tank's drainage is shut off. One-way check valves are installed at the outlets of both the large and small water pumps.

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